What is the preferred initial strategy for a patient presenting with acute coronary syndrome requiring intervention within 2-24 hours, comparing Percutaneous Coronary Intervention (PCI) and Coronary Artery Bypass Grafting (CABG)?

PCI vs CABG in Acute Coronary Syndrome: Timing Within 2-24 Hours

Direct Answer

For patients with acute coronary syndrome requiring intervention within 2-24 hours, PCI is the preferred initial strategy, with CABG reserved for specific anatomic indications (left main disease, complex multivessel disease with high SYNTAX score) or failed PCI. 1

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STEMI Patients: PCI is Overwhelmingly Preferred

Immediate Intervention (<2 Hours)

• Primary PCI should be performed within 90 minutes of first medical contact (or 120 minutes if transfer required) to reduce mortality. 1
• If PCI delay exceeds 60 minutes in patients presenting <2 hours from symptom onset, fibrinolysis may be considered, followed by routine angiography and PCI within 3-24 hours. 1
• The mortality benefit of immediate PCI over fibrinolysis is strongest when door-to-balloon time is <90 minutes. 1

Delayed Presentation (2-24 Hours)

• For STEMI patients presenting 12-24 hours after symptom onset, PPCI remains reasonable to improve clinical outcomes (Class 2a recommendation). 1
• Beyond 24 hours, PCI is only indicated if there is ongoing ischemia, acute severe heart failure, or life-threatening arrhythmias. 1
• Critical caveat: PCI should NOT be performed for totally occluded infarct-related arteries >24 hours after symptom onset in stable patients without ongoing ischemia—this provides no benefit and may cause harm. 1

CABG Role in STEMI

• CABG in STEMI is indicated ONLY for:

  • Cardiogenic shock or hemodynamic instability when PCI is not feasible 1
  • Failed PCI with ongoing ischemia 1
  • Mechanical complications (ventricular septal rupture, papillary muscle rupture) 2
  • Anatomy unsuitable for PCI (left main disease, complex multivessel disease) 3

• Emergency CABG within 2-24 hours carries significantly higher operative mortality than staged procedures, but remains life-saving when PCI fails or is anatomically impossible. 1, 4

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NSTE-ACS Patients: Risk-Stratified Approach

Very High-Risk Patients (Immediate Intervention <2 Hours)

Proceed immediately to catheterization laboratory if ANY of the following are present: 5

• Hemodynamic instability or cardiogenic shock
• Recurrent or refractory chest pain despite medical therapy
• Life-threatening arrhythmias or cardiac arrest
• Mechanical complications of MI
• Acute heart failure with refractory angina

In these patients, emergency revascularization (PCI or CABG) is indicated regardless of time from symptom onset to improve survival. 1

High-Risk Patients (Early Intervention Within 24 Hours)

Perform coronary angiography within 24 hours if GRACE score >140 or any of the following: 5

• Rise or fall in cardiac troponin compatible with MI
• Dynamic ST- or T-wave changes
• GRACE score >140

The TIMACS trial demonstrated that early intervention (median 14 hours) reduced the primary ischemic endpoint from 21.0% to 13.9% (HR 0.65, P=0.006) specifically in patients with GRACE >140. 5

Intermediate/Low-Risk Patients (Delayed Strategy)

• For GRACE score ≤140, angiography can be safely delayed beyond 24 hours or managed with selective invasive approach. 5, 6
• Perform noninvasive stress testing or coronary CT angiography before discharge to identify occult high-risk anatomy. 6

PCI vs CABG Decision in NSTE-ACS

After diagnostic angiography, revascularization strategy depends on coronary anatomy: 3

• Single-vessel disease: PCI is first choice 3
• Left main or triple-vessel disease: CABG is recommended, particularly with LV dysfunction 3, 7
• Multivessel disease in diabetics: CABG provides superior long-term outcomes (HR 0.74 for death/MI/stroke, P=0.036) compared to PCI 7

Critical timing consideration: If CABG is chosen, it should ideally be delayed 3-7 days after admission to allow dual antiplatelet therapy washout and reduce surgical bleeding risk, UNLESS the patient has cardiogenic shock, life-threatening arrhythmias, or failed PCI. 2

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Key Technical Considerations

For PCI (When Chosen)

• Use radial access as standard approach to reduce bleeding complications 3
• Drug-eluting stents are recommended over bare-metal stents regardless of clinical presentation 3
• In STEMI with multivessel disease, treat culprit vessel first, then stage complete revascularization 3

For CABG (When Chosen)

• Mechanical circulatory support before CABG may improve outcomes in cardiogenic shock 1
• Emergency CABG within 2-24 hours has acceptable outcomes when performed for appropriate indications (failed PCI, unsuitable anatomy) 1, 4
• The median time from randomization to CABG in the SHOCK trial was 2.7 hours, demonstrating feasibility of rapid surgical revascularization 1

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Common Pitfalls to Avoid

1. Do not delay PCI beyond 120 minutes in STEMI patients waiting for CABG evaluation—every 10-minute delay beyond 60 minutes adds 3-4 deaths per 100 patients with cardiogenic shock. 1

2. Do not perform PCI on totally occluded infarct-related arteries >24 hours after symptom onset in stable patients—the OAT trial showed no benefit and potential harm. 1

3. Do not rush to emergency CABG in stable NSTE-ACS patients—delaying 3-7 days reduces bleeding complications from dual antiplatelet therapy without increasing ischemic events. 2

4. Do not use GRACE score for 6-month mortality when deciding timing—use GRACE score for in-hospital death, as this is what TIMACS and VERDICT trials validated. 5

5. Do not skip Heart Team discussion in patients with complex multivessel disease—the decision between PCI and CABG significantly impacts long-term outcomes and requires interdisciplinary deliberation. 4, 8